>>>> This patch tries to optimize TMS clocks by compacting multiple clocks >>>> into one FT2232 command. This gives us 6% flash program time reduction. >>>> And it gives us more performance improvement for gdbproxy when loading >>>> program via our gnICE and gnICE+ cables. I think this will help other >>>> JTAG cables based on FT2232(H). >> >> Haven't had a chance to look at the code yet. What is the mechanism >> behind compacting clocks? With the current code, URJ_TAP_CABLE_CLOCK >> would stuff (compact?) n requested clocks into a sequence of FT2232 >> commands, each one clocking 7 times. In which spot did you find further >> optimization potential? >> > I don't see code in current svn to "stuff n requested clocks into a > sequence of FT2232 commands, each one clocking 7 times." Or I might have > missed something.
I was referring to ft2232_clock_schedule. > Another more interesting example is it will optimize > > 0x4b 0x00 0x7f 0x4b 0x00 0x7f 0x4b 0x00 0x00 0x4b 0x01 0x7f > 0x4b 0x00 0x00 0x4b 0x00 0x00 > > into > > 0x4b 0x06 0x1b So your patch compacts multiple clock actions from the todo queue into an optimized sequence of ft2232 commands. Very interesting, indeed. Such look-ahead functionality is missing completely in the current driver. What is the reason to introduce the URJ_TAP_CABLE_CLOCK_COMPACT action? Would this mean that all upper layer code needs to be adapted to benefit from the compaction? It would be nice to implement the look-ahead based on just the existing URJ_TAP_CABLE_CLOCK action - completely transparent for the upper layers. Do you see a chance for that? Best regards Arnim ------------------------------------------------------------------------------ The Planet: dedicated and managed hosting, cloud storage, colocation Stay online with enterprise data centers and the best network in the business Choose flexible plans and management services without long-term contracts Personal 24x7 support from experience hosting pros just a phone call away. http://p.sf.net/sfu/theplanet-com _______________________________________________ UrJTAG-development mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/urjtag-development
